Control system



Feb. 16, 1943.

J. L. BARKER CONTROL SYSTEM Filed March 50, 1940 Y v l I 7 j A .b C

I NVENTOR JOHN L BAR/(ER Patented Feb. 16, 1943 CONTROL SYSTEM John L. Barker, Norwalk, Conn, assignor to Automatic Signal Corporation, East Norwalk, Conn., a corporation of Delaware Application March 30, 1940, Serial No. 327,020

13 Claims.

This invention relates generally to a control system for operating counting devices or indicating devices and the like. More particularlythe invention relates to a control system employing a multiple switch treadle and a group of relays actuated thereby to operate counting devices only responsive to actuation of the multiple switches in an overlapping sequence.

Control systems in accordance with the invention are particularly useful in the counting of road vehicle trafilc at toll checking points for example where a multi-contact treadle in the roadway is actuated by a vehicle wheel rolling over its contacts in sequence and it is desired to operate one counter for recording vehicles passing in a forward direction and another counter for vehicles passing in the reverse direction, and where it is desired to have the counting of vehicle axles as accurate as possible and substantially free ofactuation by pedestrians or toll collectors or random closure of one or more of the treadle contacts.

Toll checking systems are ordinarily arranged to count the number of axles and in some cases supplementary manual classification is made of the various types of vehicles having different numbers of axles. In some instances the toll rate is related to the number of axles, and in the case of restricted roads such as parkways the traffic is frequently limited to the two axl pleasure vehicles.

Itis an object of this invention to provide an improved control system for operation of a counter or other electrical device responsiv to sequential actuation of the switches of a multiple switch device.

A further object of the invention is to provide an improved control system for operating one or more counters responsive to actuation of a multiple switch treadle substantially only by a vehicle wheel rolling thereover and in accordance with the forward or reverse direction of movement of such wheel.

Another object of the invention is to provide a control system for operating an electrical device responsive to actuation of a plurality of switches in overlapping sequence. in which the continuous closing of one of the switches by mechanical or electrical failure or by other means will not prevent proper operation of the electrical device by sequential actuation of the remaining switches.

Another object of the invention is the provision of a control system employing a multiple switch treadle for actuation of one counter or other electrical device by a wheel rolling over the treadle and operating the switches in overlapping sequence in a forward direction and another such counter or device by a wheel similarly rolling over the treadle in the reverse direction, and in which any rolling back and forth of the wheel before leaving the treadl finally in one direction either will operate the counter for that one direction only once, or, if the wheel rolls sufficiently far back and forth, will operate the counters for both directions with the counter for such one direction operated once more than that for the opposite direction.

A further object of the invention is the provision of an improved relay system for operation by I a four switch actuating device to provide an output impulse responsive to actuation of the four switches in a progressive sequence in which at least three of the switches are actuated concurrently.

Referring now to the drawing negative and positive power supply wires l0 and II are shown at the left and right sides.

A multiple switch treadle B is shown schematically in cross section in the upper part of the drawing, with the several switch contacts i, 2, 3 and 4 arranged side-by-side and adapted to engage contact plate'S individually when actuated. The treadle 6 is shown in the drawing with the common plate 5 over the contact plates l, 2, 3 and 4 for simplicity of illustration in the drawing, but is preferably placed in the surface of a roadway with the plate l, 2, 3 and 4 over the common plate 5. Four separate plates may be used in place of the common plate 5 so that both upper and lower plates are entirely separate switches if desired, but in any case the four switches in the treadle 6 are spaced so closely side-by-side that a vehicle wheel rolling over the treadle will close the switches in an overlapping sequence in which at least three switches are closed concurrently.

The four switch treadle 6 may be made with the assembly of switches all sealed in an outer envelope oi. rubber or other flexible insulating material of a rubber covering for the plates I, 2, 3, 4 may be bonded to. plate 5 and the latter made more rigid where the plate 5 is under plates I, 2, 3, 4 for example. The plate I, 2, 3, 4, 5 are preferably of relatively narrow width and considerable length extending across a trafiic lane in the case of use with road traffic for example and the plates i, 2, 3 and 4 are kept properly spaced laterally from each other preferably by separation strips of rubber and these plates may be maintained normally separated from plate by employing resilient separation strips or by employing other very narrow separation strips extending transversely across the several plates and spaced at intervals along the length of the treadie.

The narrower plates I, 2, 3 and 4 are preferably resilient and the separation strips are narrow enough to permit the individual plates to flex on either side into contact with the bottom common plate even though the tire of the vehicle wheel rides directly over the separation strip.

The details of construction of the treadle are in general immaterial to the subject matter of the present control system except that the system is designed for operation by an overlapping sequence of closure of the treadle switches as will be-more fully described below.

In the case of a wheel rolling from left to right, which is hereafter referred to as the forward direction, plate I will first contact with plate 5, then plate 2 will contact with plate 5 while I and 5 remain in contact, then plate 3 contacts with plate 5 while I and 2 are in contact with 5. Next plate 4 contacts with plate 5, plate I breaks contact with plate 5, and finally plates 2, .3 and 4 break contact with plate 5 in succession as the wheel continues to roll forward and off the treadle. It is not essential that all four plates I, 2, 3 and 4 be in contact with plate 5 concurrently but the four switches must be closed in se quence with a progressive overlap of closure of at least three switches for proper operation of the complete system.

In the case of a wheel rolling over the treadle from right to left (reverse direction) the plate 4 is first brought into contact with plate 5 and then 3, 2, and I contact with 5 in sequence, with the plates separating in the order 43-2--i, and with overlap of contact of plates 4, 3, and 2 with 5 and then overlap of contact of 3, 2 and I with 5 in order during the sequence.

Shown below the plates I, 2, 3, 4 in the drawseveral seconds for example and the time relay T is preferably of the quick reset type.

Time delay relay devices of the type in which a condenser is charged through a control resistance to a predetermined voltage to operate an electronic tube and relay are particularly suited to this timing operation, and an example is disclosed in the Patent 1,909, 871 issued to F. G. Kelly, Jr.

The printer 6! indicated schematically in the drawing would ordinarily be of electro-magnetic type to print a record, at the side of the timed traffic count record tape, used in toll checking for example, of the instances of excessive time of concurrent actuation of two or more switches of the tr'eadle. Any one or more of the several forms of alarm devices such as lamp L, printer 61, or bell BL may be omitted if desired.

ing is a group of relays A, B, C, D connected to the respective, plates, so that each relay will be operated individually when its associated plate is tively, the right side of relays being connected to wire 9.

The relays A, B, C and D when operated in the proper sequence operate relay P and in cooperation with relay P operate the relays R and R8 for a wheel rolling in the reverse direction or operate the relays F and F8 for a wheel going in the forward direction. The relay RS operates the electro-magnetic counter or other electrical device RC for actuation in the reverse direction and the relay FS operates the similar counter or electrical device FC for actuation in the forward direction. s

The relay P is operated by concurrent closure of any two of the contacts I, 2, 3, 4 and in turn operates a retarded pickup time delay relay T to operate an alarm lamp L, a printer 61 and a bell IBL if the concurrent contact closure persists more than the tim delay interval for which the relay T is set. The time may be of the order of when the relay is deenergized and is opened when the relay is energized.

Similarly relay B has four make contacts bi to D4 inclusive and one break contact b5, relay C has four make contacts cl, c2, c3, c5 and one break contact 04, and relay D has four make contacts dI, d2, d3, (15 and one break contact d4.

Relay P has two make contacts pl and p2 and one break contact p3. Relay R has two make contacts TI and T3 and one break contact 12, and relay RS has two make contacts rs! and rs2. Relay F has two make contacts 1! and f3 and one break contact f2, and relay FS has two make contacts fsl and ,f's2. Relay T has one make contact tI.

Electromagnetic devices RC and F0 are shown as counters, the coils RC and FC operating the armatures re! and f0! respectively to actuate the respective counter ratchet wheels ii and 10, and to open the contacts 7'02 and fa? respectively upon actuation of the counter wheel. The bar 12 is connected to armature rat to actuate arm 16 to open contact r02 only when the counter ratcheting armature rcl has been pui 2d down far enough by the coil RC to assure ad vance of the counter wheel I0 one digit. Bar 13 serves a similar purpose on arm "ll to open contact I02 when coil F0 is energized to advance counter wheel H The counter ratchet arrangements are shown with the counter advanced one step on the energizing stroke of the armatures rcl and jci but it will be appreciated that the ratchet arrangement could be reversed if desired to have the armature take the next tooth of the ratchet wheel on the energizing stroke and advance the ratchet wheel on the return stroke by'spring action.

All of the armatures and contacts of the several relays and electromagnetic devices are shown in their normal deenergized condition in the drawing as in the absence of treadle actuation, and these elements are restored to their normal condition by spring action or other suitable methods.

It will be understood that other contacts may be added if desired to the electromagnetic de" vices RC andlC. the relay T or other relays for operation of indicating devices or the like, or the armatures rcl and jcl may be arranged to operate contacts for signalling circuits if it is desired to use the control system of the invention for signalling instead of counting.

Considering now the operation of the system in more detail responsive to actuation of the treadle switches by a rolling wheel for example, assume first the wheel rolls over the treadle in the forward direction, actuating the switches in the order l-2-l-l.

Plate I first engages plate 5 and completes a circuit from negative power wire l via wire 1, plate I, plate I, wire I, relay A, wire 9 to positive power wire ll, thus energizing relay A and causing the latter to close its make contacts and open its break contact a5. plate while plate I is still engaged with plate 5 by the pressure of the wheel, and this closes a circuit from negative power via wire 1, plates 5 and 2, relay- B and'wire 9 to positive power, thus energizing relay B while relay A remains energized.

was relays A and B now both energized one of a group of several circuits for energizing relay P is completed via contacts al and bl. These several circuits for relay P involve different pairs of the first three contacts of the relays A, B, C, and D in combinations of two at a time. in each case the circuit through the pair of contacts connects negative power via wire it to relay P and the other side of relay P is connected via wire ii to positive power.

The first of these circuits for relay P includes ccntact al, wire l2, contact bl and wire I! to wire ll and relay P, and is completed'to energize relay P as soon asthe wheel has rolled onto plates l and 2 as stated above, and relay P closes its make contacts pl and p2 and opens its break contact 323.

Closure of contact pi completes a circuit from negative power via wires 00, 6|, contact pl, wire 6!. relay '1, but relay '1 is of the retarded opersting time delay type and will close its contact tl only after continuous energlzation for a predetermined time period of several seconds for example provided -relay P is continuously energized for such time period. In the latter case relay '3? closes its contact fl and completes a circuit via wires ll, N, contact tl, wire 85 to alarm lamp L, and via wire 38 to alarm bell BL, and printer II, as previously described.

Under normal conditions of operation. by a vehicle wheelhowever the wheel moves over the tz-eadle quite rapidly and the relay P and relay T are not energized sul'licientlv long to permit time delay relay T to operate its contact tl.

Returning to the sequence of operations as the wheel continues to roll forward over the treadle, the operation of contacts p2 and p3 by energize tion of relay P by closing of contactsal and bl has no immediate e' 'ect and the significance will be described subsequently below.

With the concurrent actuation of plates l and 2 and energization of relays A and B, the closure of contacts at and: bl completes a circuit for relay P from negative power via contact o4, wire 23, contact b4, wire 24, break contact H of relay R (now dcenergized), wires 25, 2B, relay wires ii and II to positive power, thus ener gizing relay F.

Relay F is held energized by a loclcin circuit from wire 25 at relay F via wire 5!, contact ll,

Next plate 2 engages positive power.

wires 29, 30 and contact 3102 of relay P to negative power, so that after the wheel rolls forward enough to open switch l--5 and deenergize relay A and interrupt the initial operating circuit of relay F at contact al the relay 35 will remain energized as long as relay P remains energized.

As the wheel continues to roll forward so as to bring plate 3 into contact with plate 5 the relay C is energized from negative power via plate 5, and the break contact 04 of relay C is opened and the remaining make contacts are closed. Now relays A, B, and C are concurrently energized.

Another energizing circuit for relay P has been completed via contact b2, wire l9, contact c2 and wire 20 to wire H. The latter circuitwill hold relay P energized during the next step in the sequence when the wheel has rolled further to release plate i from plate 5 and thus deenergize relay A and open contact al and :12.

The auxiliary energizing circuits for relay P via contacts a2 and cl and wires l5 and IE to H, and via contacts a3 and dl and wires l1 and I! to wire ll, and via contacts b3 and at! and wires 2| and 22 to wire ll are primarily for operation of the alarm devices through relay T in case two of the plates should become permanently closed or remain closed more than the predetermined time limit of relay T, and these auxiliary circuits are not required in connection with the counter operating relay system in the normal rolling wheel-sequence.

Relay F at contact fl has prepared a circuit for energization of relay FS as soon as relays C and D are energized and relay A or relay B is deenergized, which occurs when the wheel has rolled forward far enough to release plate I from plate 5 and to engage plates 2, 3 and 4 with plate 5.

Under these conditions a circuit to energize relay FS is completed from negative power via Contact 05, wire 3i, contact d5, wire 32, contact fl, wire 33, wires 34, 35, contact a5, wires 35, 37, relay FS, wires 38, 58 to positive power, and relay FS closes its contacts fsl andfsi.

The relay PS now has a holding circuit completed from negative power via wires l8, 4!, arm 11, contact fc2 of the electromagnetic counter FC, wire ll), fsl, wires 34, 35, contact (15 and wires 36, 3'! to relay FS. Contact D5 of relay B will also serve to maintain this holding circuit when the wheel rolls far enough to deenergize relay B as plate 2 is released from plate 5.

Now the wheel is holding only plates 3 and 4 in contact with plate 5 and relay P is held energized only by a circuit from negative power vie contact c3, wire 21, contact d3, wire 28 to wire l4 and relay P, and as the wheel rolls ofi of plate 3 so that only plate 4 is held in contact with plate 5; relay C is de'enr-rgized and opens its contact c3,-which deenergizes relay P. Thus contact 123 of relay P closes and completes a circuit from negative power via contact p3, wires l2, 13, contact fs2, wire 44 through coil FC to This energizes the coil FC and pulls down armature jet to advance the counter ratchet ll one count and by insulated bar '13 opens contact ,fcZ. This in turn interrupts the holding circuit of relay FS and deenergizes relay F8 to open contact jet and deenergize coil FC and restore the armature fcl to its upper position to prepare for any subsequent counting action.

released plate 3 terrupt the holding circuit of relay F and deenergize the latter.

As the final step in the forward rolling sequence the wheel moves off the treadle releasing plate 4 and deenergizing relay D so that the apparatus is all restored to the normal condition illustrated in the drawing.

It will be observed that by the use of series circuits through the make contacts of relays AB and relays C-D and by parallel circuits through the break contacts such as ab5 of these relay pairs the permanent closure of any one of the plates I, 2, 3 and 4 against plate 5 by failure or otherwise or the grounding of any one of the plates to relay circuits of relays A, B, C, D to negative power will not interrupt the proper operation of the relays F and PS to cause a forward count, nor will this as subsequently described interrupt proper operation of relays R and RS to cause a reverse count. ,Relay F will be energized as plate 2 is operated'ito close contact b4 by the wheel rolling forward for example, and relay FS will be energized as the plate 2 is released by the wheel to close contact b5, even if relay A alone were permanently energized for example.

However, if relay B alone were permanently energized relay F would be energized by contact a4 upon actuation of plate I and relay FS would be energized by contact a5 upon release of plate I in the forward direction the operation of relays C and D remaining the same as usual as previously described for the forward direction.

If relay C alone should be permanently energized, the relays F and FS would be energized as usual in the forward direction. In any case if any one of the relays A, B and C alone was permanently energized the counter FC would not be operated until the wheel rolled entirely off the treadle to release plate 4 and relay D and interrupt the last circuit for relay P and release relay P so as to complete the counter operating circuit at contact p3. This merely delays the count momentarily but does not prevent a proper count, the forward count being completed via contact fs2 to energize coil FC and release relay FS at contact fc2 to release coil PC at contact fs2 as previously described.

Now considering a wheel rolling in the reverse direction actuating the plates in the order 4-32-I, relay D is first energized as plate 4 is actuated. Then relay C is next energized as plate 3 is also actuated, and relay P is energized by contacts 03 and 013 over the circuit previously described. As the wheel continues over plates 2 and I the relay P is held energized by the pairs of contacts of relays C and B and those of relays B and A.

With relays D and C both energized when the wheel rolling in reverse direction has actuated plates 4 and 3, a circuit is completed to energize relay R, from negative power via contact 05, wire'3I, contact d5, wire 32, contact f2, wires 45, 46, through relay R and wires 41, 58 to positive power. Relay R thus closes its contact r3 providing a holding circuit from negative power via contact p2 wire 30, contact r3, wire 46 to relay R. Relay R also prepares a circuit for energizing relay RS as soon as the wheel has rolled in reverse direction sufficiently to operate plates 2 and I and relays B and A and to release plate 4 or plate 3, and relay D or C the circuit for relay RS being then completed from negative power via contact a4, wire 23, contact 114, wire 24, contact rI, wires 48, 49, contact (14 (or wire 50, contact 04, wire 5|), wire 52, through relay RS, wires 53, 58 to positive power.

Relay RS now completes its holding circuit via its contact rsI and contact 1'02 of the reverse counter, wires 56, 18 to negative power, the holding circuit also including contacts 64 and d4 in parallel.

As soon as the wheel has rolled far enough to release all but plate I and relay A, the last circuit for relay P is interrupted and contact p3 closes completing a circuit via contact rs2 to the reverse electromagnetic device RC so that the armature rcl will be pulled down to operate the reversecounter ratchet I0, and the insulated bar 12 will operate arm 16 to open contact 102 to interrupt the holding circuit of relay RS and release this relay to open its contact rs2 to deenergize the coil RC and release armature rcI will :cross the treadle after toll is paid and the 4 car moves forward in leaving the toll station. However, the restriction of the traffic lanes at and near the toll station to permit cars passing around or crossing lanes extends for only a short distance and the treadles cannot be placed very far beyond the station. For this reason car drivers sometimes overrun the station somewhat and actuate the treadle in a forward direction and then back up to pay toll, again proceeding forward over the treadle after paying toll.

The present invention provides for this condition by the count in both reverse and forward directions so that the forward count less the reverse count provides an accurate net forwar count.

Another problem in toll check counting is that the front wheels of a car may roll partway onto the treadle. Such a condition is sometimes also caused by the toll collectors recalling the driver on account of an error in change or some other question about the money or the driver returns to ask some question.

It is a feature of the present invention that such rolling back and forth will not interfere with a correct net forward count. The forward preparatory relay F and the reverse preparatory relay R, are interlocked electrically by having the initial energizing circuit of each pass through a break contact of the other, F being energized through contact r2 and R being energized through contact f2, so that the initial operation of one prevents the operation of the other until the first has released again on completion of the appropriate count. Whichever of relays F and R is energized, is locked in over a holding circuit via make contact p2 of relay P as previously described. Also the completion of the operating circuits to the respective counters depends on closure of break contact 123 of relay P. Thus as long as any two of the plates remain actuated as the wheel rolls back and forth then relay P will remain energized over one of the several circuits of the first four sets of contacts of relays A, B, C, D, and whichever relay R or F is operated will remain locked in and the other locked out, and neither counter will be operated. The counter will be operated only by the rolling of .the wheel off all but one plate in the original direction so as to release relay P which in turn will operate the appropriate counter and will also release whichever relay R or F was energized by the initial movement in the original direction. Since the counter also is reset to normal by releasing relay FS or RS as the case may be, the system is then ready to operate for another count.

It will be observed that both the initial energizing circuit and the holding circuit for the relay FS include break contacts (15 and 125 on relays A and B, and both such circuits for relay RS include break contacts c4 and d4 on relays C and D, as previously described. Thus if a wheel rolls forward to actuate plates 3 and 4 and release plate I the relay FS will be initially energized as previously described by way of contact ii .of the preparatory relay F, but if the wheel then rolls backward to reactuate plate I the relay contact a5 will again open and since contact b5 is also open the relay FS will become deenergized again. No count will then have been made since relay P has remained energized and contact p3 open. If the wheel continues backward oil the treadle, or off all but plate I, the relay P will then be released and also the relay F so that the system will be ready for the next count in either direction, so that if the wheel now again rolls forward across the treadle completely onlyone forward count and no reverse count will be recorded.

If however the wheel should initially roll forward far enough to release all but the last plate and cause a forward count, and then roll backward but not far enough to release all but the first plate and then forward again, no reverse count will be recorded because relay contact 113 will remain open and relay RS will be released by contacts c4 and d4 reopening on the final forward movement and only the first forward count will be made.

It will be appreciated that although four switches I, 2, 3, 4 and four corresponding relays A, B, C, D are employed in the present embodiment this is merely illustrative of the preferred arrangement, and more than four switches could readily be employed side-by-side and additional relays connected thereto in similar manner to relays A, B, C, D and additional contacts and circuits for relay P provided similar to those illustrated. The additional plates may conveniently be arranged between plates 2 and 3 for example and the additional relays arranged between relays B and without changing any of the circuits for relays F, R, FS, and RS if desired except that in such case the plates must be narrow enough and closely spaced enough so that the wheel will operate three adjacent plates concurrently as at present.

If desired, however, the circuits for relays F, R, FS and RS involving the series contacts at, M and 05, d and the parallel contacts a5, b5 and c4,

. d4 could be extended to include additional series or parallel contacts respectively on adjacent relays so that three adjacent plates must be operated concurrently to complete the initial operating circuits for relays F, R, FS and RS and the circuits of relay P could similarly be extended over three contacts so that energization of relay P would require actuation of three plates concurrently instead of two. This arrangement would permit the permanent closure of any two plates and still provide proper counting. In such arrangement the plates would preferably be narrower and more closely spaced if more than four plates are used.

It will also be appreciated that the fourth plate 4 and relay D could be omitted if desired to provide a three switch treadle employing plates I, 2 and -3 and relays A, B and C in which case the contacts di and d5 would be transferred to relay B, and the circuits would operate as previously described, the system providing the forward and reverse counting and protective features already described for the four switch treadle arrangement.

It will therefore be observed that the principles of the present circuit arrangement in accordance with the invention provide the basis for considerable variation in the number of plates and relays and further flexibility of design.

It will be understood that other rearrangements or substitutions may be made in the various parts of the system without departing from the spirit of the invention as defined by the claims.

Where the concurrent actuation of more than two plates, or at least three plates, or three or more plates is stated as required herein it will be understood that the operation of the system depends on having not less than two plates actuated at any time during the overlapping sequence and that this requires at least a momentary overlap of actuation of three adjacent plates as the actuation is transferred from plates l and 2 to plates 2 and 3 and so on through the sequence.

I claim:

1. A control system including in combination a multiple switch treadle having more than two switches arranged closely side-by-side for actuation in overlapping sequence, an electrical device, and relay means connected between said switches and said device to operate said electrical device responsive to actuation of all said switches in a progressive sequence in which more than two switches are actuated concurrently and in which said means are so operative responsive only to actuation of the first two switches concurrently before the last two switches are both actuated, followed by actuation of said last two switches and release of at least one of said first two switches while said last two switches remain actuated, followed by release of at least all except the last switch.

2. A control system including a multiple switch treadle adapted to be embedded in a roadway for actuation of the switches in sequence by a vehicle wheel rolling over the treadle, said switches being so closely spaced that more than two switches will be actuated concurrently by the"- wheel in such sequence, an electrical device, and means for operating said device responsive only to actuation of all of said switches in a sequence in which the first two switches are concurrently actuated prior to concurrent actuation of two others of said switches, and one of the said first two switches is released while said other two switches are concurrently actuated and at least the first three switches are thereafter released.

3. A control system including a multiple switch treadle having more than two switches arranged closely side-by-side for actuation in overlapping sequence, an electrical device, and means connected between said switches and said device to operate said device responsive to closure of all ofsaid switches in sequence with never less than in such sequence and with any one switch re-,

maining continuously closed throughout the entire sequence.

5. A control system including a multiple switch treadle having more than two switches arranged closely side-by-side for actuation in overlapping sequence, an electrical device, and means connected between said switches and said device to operate said device responsive to closure of all of said switches in sequence with at least three adjacent switches closed concurrently during the sequence, means for releasing said device upon operation of the same, and means to prevent any double operation of said device if all of the treadle switches are first closed in sequence in one direction and then the last switch in that direction is released after preceding adjacent switches have been reclosed and then such preceding switches are released again and thereafter the last switch is released.

6. A control system including more than three switches arranged closely side-by-side for operation in a progressive sequence in which more than two adjacent switches are closed concurrently, relays connected to be operated by closure of the respective switches, another relay connected to be operated by concurrent operation of any two of the first mentioned switches, an additional relay connected to be operated by concurrent first operation of the first two of the first mentioned relays, and to be maintained operated by operation of said other relay, a furrelay connected to be operated by concurrent operation of said additional relay and of a third and fourth of said first relays together with concurrent release of one or" said first two relays, and an output circuit controlled by operation of said further relay.

7. A control system including more than three switches arranged closely side-by-side for operation in a progressive sequence in which more than two adjacent switches are closed concurrently, relays connected to be operated by closure of the respective switches, another relay connected to be operated by concurrent operation of any two of the first mentioned switches, an additional relay connected to be operated by concurrent first operation of the first two of the first mentioned relays, and to be maintained operated by operation of said other relay, a further relay connected to be operated by concurrent operation of said additional relay and of a third and fourth of said first relays together with concurrent release of one of said first two relays, and an output circuit controlled by operation of said further relay, a second additional relay connected to be operated by concurrent first operation of said third and fourth relays with the first mentioned additional relay nonoperated and to be maintained operated by operation of said other relay, a second further relay aeirsco tion of said second additional relay and of said first two relays together with concurrent release of said third relay or said fourth relay, and an output circuit controlled by operation of said second further relay.

8. A relay system including first, second, third and fourth relays, each having make contacts and a break contact, a fifth relay having break and make contacts, a plurality of operating circuits for said fifth relay each including in series a combination of make contacts of a different pair of the first four relays, a sixth relay and a seventh relay having break and make contacts, and an eighth relay and a ninth relay having make contacts, an operating circuit for said sixth relay including a break contact of said seventh and make contacts of said first and second relays in series,

' an operating circuit for said seventh relay including a break contact of said sixth relay and make contacts of said third and fourth relays in series, lock-in circuits for the respective sixth and seventh relays including a make contact of said fifth relay, an operating circuit for said eighth relay including make contacts of said third, fourth and sixth relays all in series with parallel break contacts of said first and second relays, an operating circuit for said ninth relay including make contacts of said first and second and seventh relays all in series with parallel break contacts of said third and fourth relays, and two output circuits one including a break contact of said fifth relay and a make contact of said eighth relay in series and the other output circuit including a break contact of said fifth relay and a make contact of said ninth relay in series.

9. A relay system as in claim 8 with the addition of two electromagnetic devices operated by the respective outputcircuits and having break contacts opened by operation of the respective said electromagnetic devices, and a lock-in circuit for said eighth relay including the break contact of the electromagnetic device operated by said one output circuit, and a lock-in circuit for said ninth relay including the break contact of said other electromagnetic device.

10. A control system including in combination a multiple. switch treadle having more than two switches arranged closely side-by-side for actuation in overlapping sequence, two electrical devices, and relay means connected between said switches and said electrical devices to operate one of said devices and prevent operation of the other device responsive to actuation of all said switches in a progressive sequence in one direction in which two or more switches are actuated concurrently and to operate the other of said devices and prevent operation of the said one device responsive to actuation of all said switches in a progressive sequence in the opposite direction in which two or more switches are actuated concurrently, said relay means including means assuring such operation of said devices despite continuous actuation of any one of said switches throughout the entire sequence.

11. A control system including'in combination a multiple switch treadle having more than two switches arranged closely side-by-side for actuation in overlapping sequence, two electrical devices, and relay means connected between said connected to ,be operated by concurrent operaswitches and said electrical devices to operate one of said devices and prevent operation of the other device responsive to actuation of all said switches in a progressive sequence in one direction in which two or more switches are actuated concurrently and to operate the other of said devices and prevent operation of the said one device responsive to actuation of all said switches in a progressive sequence in the opposite direction in which two or more switches are actuated concurrently, said relay means including circuit means grouping the switches in pairs with respect to operation of the relay means for assuring such operation of said devices despite continuous actuation of any one of said switches throughout the entire sequence.

12. A control system including in combination a multiple switch treadle having more than two switches arranged closely side-by-side for actuation in overlapping sequence, two electrical devices, and relay means connected between said switches and said electrical devices to operate one of said devices and prevent operation of the other device responsive to actuation of all said switches 'in a progressive sequence in one direction in which two or more switches are actuated concurrently and to operate the other of said devices and prevent operation of the said one device responsive to actuation of all said switches in a progressive sequence in the opposite direction in which two or more switches are actuated concurrently, said relay means including circuit means grouping the switches in pairs with respect to operation of the relay means for requiring concurrent operation of said switches in successive pairs for operation of said relay means, and also for requiring release of either one switch of successive pairs for operation of said relay means as said switches are actuated and released in sequence,

whereby continuous actuation oi any one switch will not interfere with operation of the respective devices by said relay means. I

13. A control system including in combination a multiple switch treadle having more than two switches arranged closely side-by-side for actua tion in overlapping sequence, an electrical device, and relay means connected between said switches and said device to operate said electrical device responsive to actuation of all said switches in a progressive sequence in which more than two switches are actuated concurrently and in which said means are so operative responsive only to actuation of the first two switches concurrently before the last two switches are both actuated,

followed by actuation of said last two switches and release of at least one of said first two switches while said last two switches remain actuated, followed by release of at least all except the last switch, said relay means including relays operated individually by the respective switches and further relays operated by the first mentioned relays including relay operating circuits for said further relays including pairs of make contacts of said first mentioned relays in series and pairs of break contacts of said first-mentioned relays in parallel whereby continuous operation of any one of said first-mentioned relays will not interfere with proper operation of the electrical device by said relay means.

J OHN L. BARKER. 

